Open Branes in Space-Time Non-Commutative Little String Theory

TL;DR

This paper proposes two new six-dimensional non-gravitational string theories with open branes, connecting space-time non-commutative Little String Theories, NCOS, and OM theories through dualities and supergravity duals.

Contribution

It introduces space-time non-commutative Little String Theories with open branes, establishing their spectra, dualities, and relations to existing theories like NCOS and OM.

Findings

The (2,0) theory includes an open membrane and reduces to OM theory.

The (1,1) theory includes an open string and reduces to 5+1 dimensional NCOS.

Theories are connected via T-duality and S-duality, linking NCOS and OM theories.

Abstract

We conjecture the existence of two new non-gravitational six-dimensional string theories, defined as the decoupling limit of NS5-branes in the background of near-critical electrical two- and three-form RR fields. These theories are space-time non-commutative Little String Theories with open branes. The theory with (2,0) supersymmetry has an open membrane in the spectrum and reduces to OM theory at low energies. The theory with (1,1) supersymmetry has an open string in the spectrum and reduces to 5+1 dimensional NCOS theory for weak NCOS coupling and low energies. The theories are shown to be T-dual with the open membrane being T-dual to the open string. The theories therefore provide a connection between 5+1 dimensional NCOS theory and OM theory. We study the supergravity duals of these theories and we consider a chain of dualities that shows how the T-duality between the two theories is connected with the S-duality between 4+1 dimensional NCOS theory and OM theory.